PCBs stack Insulating

  • Thread starter Précis d'electronique
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Précis d'electronique

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HI,

I have 2 PCBs stacked with standoffs the one on the top is a SMPS, and
the one on the botttom has some TH components that can bridge with
some in the top PCB, I was wondering how it is normally do to isolate
stacked PCBs, there is no room for a bigger stand off.

My first try was to use FR4, without copper, I don't even know if I
can buy that.


Do you have any clues?

thank you

BTW it is for production
 
Précis d'electronique wrote:
I have 2 PCBs stacked with standoffs the one on the top is a SMPS, and
the one on the botttom has some TH components that can bridge with
some in the top PCB, I was wondering how it is normally do to isolate
stacked PCBs, there is no room for a bigger stand off.

They usually don't design stuff that's already broken.
Click to expand...

Hope This Helps!
Rich
 
On 18 mar, 15:58, Rich Grise <ri...@example.net.invalid> wrote:
Pr cis d'electronique wrote:

I have 2 PCBs stacked with standoffs the one on the top is a SMPS, and
the one on the botttom has some TH components that can bridge with
some in the top PCB, I was wondering how it is normally do to isolate
stacked PCBs,  there is no room for a bigger stand off.

They usually don't design stuff that's already broken.

Hope This Helps!
Rich
Click to expand...
Well, I just want to be sure that there is something between PCBs and
not only air.

For example, if it falls the impact can cause a short.
 
On 18 mar, 16:35, Michael Black <et...@ncf.ca> wrote:
On Fri, 18 Mar 2011, Précis d'electronique wrote:
HI,

I have 2 PCBs stacked with standoffs the one on the top is a SMPS, and
the one on the botttom has some TH components that can bridge with
some in the top PCB, I was wondering how it is normally do to isolate
stacked PCBs,  there is no room for a bigger stand off.

My first try was to use FR4, without copper, I don't even know if I
can buy that.

Do you have any clues?

I'm not sure what it is, but I've taken things apart and there's a sheet
of semi-clear something between switching supplies and the chassis.  I
guess some kind of plastic, you just have to find out what's being used.

    Michael
Click to expand...
Yes, I have seen that too, but I would put some flame retardant, or
add EMI sheets (expensive)

I have 16mm between PCBs, In spite of it I am sure that I can make it
surer

Thank you
 
On Fri, 18 Mar 2011 14:31:52 -0700 (PDT), Précis d'electronique
<ee.jcesar@gmail.com> wrote:

HI,

I have 2 PCBs stacked with standoffs the one on the top is a SMPS, and
the one on the botttom has some TH components that can bridge with
some in the top PCB, I was wondering how it is normally do to isolate
stacked PCBs, there is no room for a bigger stand off.

My first try was to use FR4, without copper, I don't even know if I
can buy that.
Click to expand...
Sure, it's readily available. We also use a few mil thick sheets of lexan.
You're probably going to want something that's UL 94V-0, or similar, rated.

Do you have any clues?

thank you

BTW it is for production
Click to expand...
Does it need UL or other test labs certification?
 
On 2011-03-18, Michael Black <et472@ncf.ca> wrote:
This message is in MIME format. The first part should be readable text,
while the remaining parts are likely unreadable without MIME-aware tools.

--8323328-1778911484-1300487725=:10735
Content-Type: TEXT/PLAIN; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: QUOTED-PRINTABLE

On Fri, 18 Mar 2011, Pr=E9cis d'electronique wrote:

HI,

I have 2 PCBs stacked with standoffs the one on the top is a SMPS, and
the one on the botttom has some TH components that can bridge with
some in the top PCB, I was wondering how it is normally do to isolate
stacked PCBs, there is no room for a bigger stand off.

My first try was to use FR4, without copper, I don't even know if I
can buy that.
Click to expand...

Do you have any clues?

I'm not sure what it is, but I've taken things apart and there's a sheet=20
of semi-clear something between switching supplies and the chassis. I=20
guess some kind of plastic, you just have to find out what's being used.
Click to expand...
I've seen clear plastic that I understand to be polycarbonate (eg:
Lexan(tm)) and also card-weight transformer paper (eg: Nomex(tm))
used as an insulator around mains voltages,

but for the application under discussion the FR4 sounds like a better
solution as I expect it would be more resistant to puncture under
physical shock and vibrations.

--
⚂⚃ 100% natural
 
The cheap way is 'fish paper', a kind of dense paper
like oaktag.
 
"Précis d'electronique" <ee.jcesar@gmail.com> wrote in message
news:0657dd9b-d930-478d-b8d2-5314505dd84b@r19g2000prm.googlegroups.com...
On 18 mar, 16:35, Michael Black <et...@ncf.ca> wrote:
On Fri, 18 Mar 2011, Précis d'electronique wrote:
HI,

I have 2 PCBs stacked with standoffs the one on the top is a SMPS, and
the one on the botttom has some TH components that can bridge with
some in the top PCB, I was wondering how it is normally do to isolate
stacked PCBs, there is no room for a bigger stand off.

My first try was to use FR4, without copper, I don't even know if I
can buy that.

Do you have any clues?

I'm not sure what it is, but I've taken things apart and there's a sheet
of semi-clear something between switching supplies and the chassis. I
guess some kind of plastic, you just have to find out what's being used.

Michael

Yes, I have seen that too, but I would put some flame retardant, or
add EMI sheets (expensive)

I have 16mm between PCBs, In spite of it I am sure that I can make it
surer.
Click to expand...
Is that 16mm correct? That is 0.629 inches, over 5/8s of an inch.
I'm not sure you need anything, You might try a piece of soft rubber or firm
foam
in the center between the boards if it is a long span between standoffs.

Mikek
 
On 19 mar, 18:29, "amdx" <a...@knology.net> wrote:
"Pr cis d'electronique" <ee.jce...@gmail.com> wrote in message

news:0657dd9b-d930-478d-b8d2-5314505dd84b@r19g2000prm.googlegroups.com...
On 18 mar, 16:35, Michael Black <et...@ncf.ca> wrote:





On Fri, 18 Mar 2011, Pr cis d'electronique wrote:
HI,

I have 2 PCBs stacked with standoffs the one on the top is a SMPS, and
the one on the botttom has some TH components that can bridge with
some in the top PCB, I was wondering how it is normally do to isolate
stacked PCBs, there is no room for a bigger stand off.

My first try was to use FR4, without copper, I don't even know if I
can buy that.

Do you have any clues?

I'm not sure what it is, but I've taken things apart and there's a sheet
of semi-clear something between switching supplies and the chassis. I
guess some kind of plastic, you just have to find out what's being used..

Michael
Yes, I have seen that too, but I would put some flame retardant, or
add EMI sheets (expensive)
I have 16mm between PCBs, In spite of it I am sure that I can make it
surer.

 Is that 16mm correct?  That is 0.629 inches, over 5/8s of an inch.
I'm not sure you need anything, You might try a piece of soft rubber or firm
foam
 in the center between the boards if it is a long span between standoffs.

                        Mikek
Click to expand...
Yes that is correct 16mm, and I need UL certification.

Could you please tell me where I can find FR4/G10 without copper?

Thank you
 
On Tue, 22 Mar 2011 08:05:56 -0700 (PDT), Précis d'electronique
<ee.jcesar@gmail.com> wrote:

On 19 mar, 18:29, "amdx" <a...@knology.net> wrote:
"Pr cis d'electronique" <ee.jce...@gmail.com> wrote in message

news:0657dd9b-d930-478d-b8d2-5314505dd84b@r19g2000prm.googlegroups.com...
On 18 mar, 16:35, Michael Black <et...@ncf.ca> wrote:





On Fri, 18 Mar 2011, Pr cis d'electronique wrote:
HI,

I have 2 PCBs stacked with standoffs the one on the top is a SMPS, and
the one on the botttom has some TH components that can bridge with
some in the top PCB, I was wondering how it is normally do to isolate
stacked PCBs, there is no room for a bigger stand off.

My first try was to use FR4, without copper, I don't even know if I
can buy that.

Do you have any clues?

I'm not sure what it is, but I've taken things apart and there's a sheet
of semi-clear something between switching supplies and the chassis. I
guess some kind of plastic, you just have to find out what's being used.

Michael
Yes, I have seen that too, but I would put some flame retardant, or
add EMI sheets (expensive)
I have 16mm between PCBs, In spite of it I am sure that I can make it
surer.

 Is that 16mm correct?  That is 0.629 inches, over 5/8s of an inch.
I'm not sure you need anything, You might try a piece of soft rubber or firm
foam
 in the center between the boards if it is a long span between standoffs.

                        Mikek

Yes that is correct 16mm, and I need UL certification.

Could you please tell me where I can find FR4/G10 without copper?
Click to expand...
http://search.digikey.com/scripts/DkSearch/dksus.dll
 
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